### About the Number 521 (five hundred twenty-one)

521 was the smallest number without a nBAB on 27 June 2018.

```MathBabbler Number Analyst (MBNA) output:
=========================================
521 is natural, counting, whole, integer
521 is odd (not even)
521 is not extremely odd
521 proper divisors are: 1,
521 has 1 proper divisors
521 is deficient (sum of divisors is 1; ratio: 0.00191939)
521 is unhappy
521 is a Squarefree Number
521 is prime (not composite)
...Twin prime with 523
...Truman Gerald (p-30) prime with 491
...Pythagorean prime
...Eisenstein (3n-1; n=174)
...Strong prime
521 is sum of two squares
...521 = 11^2 + 20^2
521 is Recaman number 1219
521 is a Lucas number(322+199)
521 is the sum of 3 distinct cubes (1^3 + 2^3 + 8^3)
521 digital root is 8
521 in octal is 01011
521 in binary is 1000001001 (is odious)
521 nearest square numbers: -37...8 (484...529 [23])
sqrt(521) = 22.8254
ln(521) = 6.25575
log(521) = 2.71684
521! is 9.17502e+1190
521 is 165.839 Pi years
521 is 26 score and 1 year
521 written as a Roman numeral is DXXI
521 is 261^2 - 260^2 and 261 + 260 = 521
521 is a multiple of 1 & it contains a 1 (A011531)
____________________________________________________
521 reciprocal is 0.0019193857965451055662188099808061420345489443378119
remainders:
1,10,100,479,101,489,201,447,302,415,503,341,284,235,266,55,29,290,295,345,324,114,98,459,422,52,520,511,421,42,420,32,320,74,219,106,18,180,237,286,255,466,492,231,226,176,197,407,423,62,99,469,1
```

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 27 June 2018